News / Science & Technology

Astronomers Say Galaxy May Be Awash with Homeless Planets

Artist's concept showing a free-floating planet with roughly the mass of Jupiter. These lone worlds, perhaps ejected from the planetary systems of their birth, are probably more common in our galaxy than stars.
Artist's concept showing a free-floating planet with roughly the mass of Jupiter. These lone worlds, perhaps ejected from the planetary systems of their birth, are probably more common in our galaxy than stars.
TEXT SIZE - +

Astronomers say the Milky Way may be swarming with nomad planets wandering through space instead of orbiting a host star, and that the galaxy may have a greater number of unmoored planets than stars.

Last year, astronomers detected about a dozen nomad planets wandering about the galaxy, using a technique called gravitational microlensing, in which the light of stars is momentarily refocused, and brightened, by the gravity of passing planets.

At that time, scientists estimated there could be two Jupiter-sized nomad planets for every typical star with orbiting planets in the Milky Way.  Jupiter, a gas giant, is the largest planet in the solar system.

A new analysis by researchers at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University in California now estimates there could be 100,000 times more homeless planets than stars.

Louis Strigari, a research scientist at Kavli, led the study that calculated the gravitational pull of the Milky Way galaxy and the amount of cosmic matter, or material, available to form nomad planets.

"We imagined that the population of a dozen or so Jupiter-mass wandering or nomadic objects is just the tip of the iceberg relative to what’s really out there in terms of our galaxy," said Strigari.  "So, if one makes assumptions about how many there are below the mass below Jupiter, then one can obtain a bound [an estimate] on how many of these actually exist.

While they might seem to be unlikely candidates for life as we know it, StrIgari says it is possible some of these wandering planets could harbor forms of bacterial life, even if they do not enjoy the heat of a sun.

“If the object has a thick enough atmosphere and say there’s tectonic activity or radioactivity going on, on the surface of the planet, the heat could get trapped by the thick atmosphere and could potentially be hospitable to microbial life,” said the research scientist.

Strigari also says there is a slight chance that two nomad planets could collide, flinging bacterial debris into other solar systems.

Astronomers hope to confirm the number of wandering planets in the next decade, when a newer generation of larger, more powerful telescopes - including the space-based Wide-Field Infrared Survey Telescope and the ground-based Large Synoptic Survey Telescope proposed by the U.S. space agency (NASA) - begins operating.

An article by Louis Strigari and colleagues on nomadic planets is published in the journal Monthly Notices of the Royal Astronomical Society.

You May Like

Russia-Ukraine Crisis Could Trigger Cyber War

As tensions between Kyiv and Moscow escalate, so too has frequency of online attacks targeting government, news and financial sites More

Egyptian Court Jails 23 Pro-Morsi Supporters

Meanwhile, Egyptian officials say gunmen have killed two members of the country's security forces More

Pakistani Journalists Protest Shooting of Colleague

Hamid Mir, a host for private television channel Geo, was wounded after being shot three times Saturday, but is expected to survive More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Ukraine, Russia, United in Faith, Divided in Politicsi
X
Michael Eckels
April 19, 2014
There is a strong historical religious connection between Russia and Ukraine. But what role is religion playing in the current conflict? In the run-up to Easter, Michael Eckels in Moscow reports for VOA.
Video

Video Ukraine, Russia, United in Faith, Divided in Politics

There is a strong historical religious connection between Russia and Ukraine. But what role is religion playing in the current conflict? In the run-up to Easter, Michael Eckels in Moscow reports for VOA.
Video

Video Face of American Farmer is Changing

The average American farmer is now 58 years old, and farmers 65 and older are the fastest growing segment of the population. It’s a troubling trend signaling big changes ahead for American agriculture as aging farmers retire. Reporter Mike Osborne says a new report from the U.S. Census Bureau is suggesting what some of those changes might look like... and why they might not be so troubling.
Video

Video Donetsk Governor: Ukraine Military Assault 'Delicate But Necessary'

Around a dozen state buildings in eastern Ukraine remain in the hands of pro-Russian protesters who are demanding a referendum on self-rule. The governor of the whole Donetsk region is among those forced out by the protesters. He spoke to VOA's Henry Ridgwell from his temporary new office in Donetsk city.
Video

Video Drones May Soon Send Data From High Seas

Drones are usually associated with unmanned flying vehicles, but autonomous watercraft are also becoming useful tools for jobs ranging from scientific exploration to law enforcement to searching for a missing airliner in the Indian Ocean. VOA’s George Putic reports on sea-faring drones.
Video

Video New Earth-Size Planet Found

Not too big, not too small. Not too hot, not too cold. A newly discovered planet looks just right for life as we know it, according to an international group of astronomers. VOA’s Steve Baragona has more.
Video

Video Copts in Diaspora Worry About Future in Egypt

Around 10 percent of Egypt’s population belong to the Coptic faith, making them the largest Christian minority in the Middle East. But they have become targets of violence since the revolution three years ago. With elections scheduled for May and the struggle between the Egyptian military and Islamists continuing, many Copts abroad are deeply worried about the future of their ancient church. VOA religion correspondent Jerome Socolovsky visited a Coptic church outside Washington DC.
Video

Video Critics Say Venezuelan Protests Test Limits of Military's Support

During the two months of deadly anti-government protests that have rocked the oil-rich nation of Venezuela, President Nicolas Maduro has accused the opposition of trying to initiate a coup. Though a small number of military officers have been arrested for allegedly plotting against the government, VOA’s Brian Padden reports the leadership of the armed forces continues to support the president, at least for now.
Video

Video More Millenials Unplug to Embrace Board Games

A big new trend in the U.S. toy industry has more consumers switching off their high-tech gadgets to play with classic toys, like board games. This is especially true among the so-called millenial generation - those born in the 1980's and 90's. Elizabeth Lee has more from an unusual café in Los Angeles, where the new trend is popular and business is booming.
Video

Video Google Buys Drone Company

In its latest purchase of high-tech companies, Google has acquired a manufacturer of solar-powered drones that can stay in the air almost indefinitely, relaying broadband Internet connection to remote areas. It is seen as yet another step in the U.S. based Web giant’s bid to bring Internet to the whole world. VOA’s George Putic reports.
AppleAndroid